1. Field
Example embodiments of the present inventive concepts relate to a heterogeneous layered structure including a graphene sheet and a hexagonal boron nitride sheet, a method of preparing the heterogeneous layered structure, and an electronic device including the heterogeneous layered structure.
2. Description of the Related Art
Generally, graphite is an allotropic form of the element carbon having a structure in which two-dimensional (2D) graphene sheets of carbon atoms are stacked. The carbon atoms of the graphene sheets are connected to each other in an extended array of hexagonal rings. Due to relatively high transparency and high conductivity, graphene may be applicable to a variety of electronic devices, for example, in an electrode for displays or solar cells.
Most graphene devices may be manufactured by transferring graphene grown by chemical vapor deposition (CVD) or mechanically isolated graphene onto a dielectric material, e.g., SiO2, Al2O3, or HfO2. However, particles or impurities may remain between the graphene and the dielectric material during the transfer, causing interfacial defects, which consequently lower the electron mobility of the graphene and cause a hysteresis on the I-V characteristics of the graphene devices.
Hexagonal boron nitride (h-BN) as a material having a 2D structure consists of boron and nitrogen atoms in an hexagonal arrangement, has a similar lattice constant to graphene, a relatively large optical phonon energy, and a relatively large band gap of about 5.9 eV, and thus is drawing attention as a 2D material for high-performance graphene electronic devices. However, currently available methods of forming a layered structure of graphene/h-BN involve transferring CVD-grown graphene or mechanically exfoliating a graphene and an h-BN layer. This process has a limitation in the manufacture of a relatively large-area, high-quality layered structure necessary for mass production of electronic devices.